hi, Thomas,

I ask them to remove and install again about the ABS sensors and also they did the reface for all rotors. problems seems getting better, but the noise still there. they ask me to go there and have a computer-scanned. will keep updating. thanks for your helps.

Response from changchingchi
6 questions asked

Thanks for the update!

Did they at least verify that my "guess" was correct? The noise
that you are hearing / feeling is the ABS activation?

The scan might not show a fault code. Remember, the ABS system is
triggered because the ABS Module "thinks" that one of the wheels
has stopped turning and because of that, it releases & applies
brake pressure rapidly and does not store a code because of that.

Thomas

Answered by exovcds
0 questions asked

I haven't taken a longer test drive. at least, it doesnt happen in 5 miles on the way to school. When they took a test drive, hit the brake very strongly and the noise came. (but when I hit it very slow, there was no noise for that moment). one of the mechanic said that is normal for some types of vehicle. Seems that now the problem only exist when hitting the brake very strongly and suddenly. ps. I guess that it is just about the abs system. but they told me the abs system looks pretty normal, nothing wrong when they checked it. forgive my bad english.

Response from changchingchi
6 questions asked

Your English is fine, I'm German... I had to learn as well! :-)

ABS activation when pressing hard (on dry flat roads) is normal.
ABS activation when pressing soft (on gravel, wet / snow roads) is normal.
ABS activation when pressing soft (on dry flat roads) is not normal.

I can drive my car for several weeks and never feel the ABS... it
all depends on the road conditions.

If it continues to happen, especially on dry flat surfaces & at
low speeds, then something is still wrong.

Continue to monitor it and see what happens.

Good luck,

Thomas

Answered by exovcds
0 questions asked

one thing here is you said that they heard the noise with a strong application, that may be just he abs unit making the noise due to the application. alot of gm cars make a whine/groan type of noise and it's only normal because it's the abs unit working.

Answered by hmac300 (expert)
17,875 answers provided

ok. thanks , but one thing I'm thinking is shouldn't it be quiet when abs is working? and feel nothing on ur feet? which mean even the abs is working but we shouldn't feel it? I probably make another video and let you guys see.

Response from changchingchi
6 questions asked

As long as the ABS light in the dash is OFF while driving, the system is ON.

Once the ABS is Activated, you feel & hear the abs pump.

During normal daily driving, you should not hear / feel the ABS, simply
because it is not needed.

If the ABS light is always ON, then the ABS is Deactivated because a
fault is detected in the system.

Thomas

Answered by exovcds
0 questions asked

hey, guys.

For this moment, I think the problems had been solved, at least I never feel anything in normal brake application. it is fine for me. what they did are checked all the abs sensors and reface the "all" rotors". also, I asked them to disconnect the battery in order to reboot the whole system. I don't know which part worked, at least it is fine right now. meanwhile, I was told the motor mounts for both sides are bad which make my car has vibration around 60-80 mph( I just finished the tire-balancing). So, I guess that will be my next thing to do...I am planning to change the motor mounts by myself. I searched so info online. I think it wont be that's hard to do, any idea? :)

Response from changchingchi
6 questions asked